Technical Field
Embodiments of the present disclosure relate generally to automotive technology and in particular to supplying air and fuel mixture to a combustion chamber.
Related Art
Often air and/or fuel are ignited in a combustion chamber to generate energy for various purposes. For example, the energy may be used to produce mechanical movement/actions. The air and fuel are mixed in a proportion to generate energy efficiently. In general, devices are used to control the supply of the air and fuel to the combustion chamber thereby controlling the energy generated. Carburetor is an example device that blends air and fuel for an internal combustion engine. Corroborator generally produces an explosive mixture of vaporized fuel and air. FIG. 1A illustrates the conventional carburetor arrangement. FIG. 1B illustrates the cross section of conventional carburetor arrangement. The prior carburetor is shown comprising elements that include venturi 105, outer air inlet 110, combustion chamber 115, throttle valve diaphragm 120, throttle slide 125, needle jet 130, jet needle 135, pilot air jet 140, floater 145, float valve 150, main jet 155, pilot jet 160, pilot mixture screw 165, throttle plate 170, chock plunger 175, float bowl 180 and spring 185. Each of the elements is described in further detail.
Venturi 105 is a tube connecting outer air inlet 110 with combustion chamber 115 of engine. The throttle valve diaphragm 120 and throttle slide 125 are interconnected. A spring 185 is placed in the hollow space provided by throttle valve diaphragm 120 and throttle slide 125. The spring 185 is tightly coupled with throttle valve diaphragm 120 and throttle slide 125. The front end of accelerator wire (cable) is connected to throttle hand bar. The rear end of accelerator wire along with spring is attached to the flat end surface of jet needle 135 along the throttle slide 125. The throttle plate 170 is used to control the flow of air in the venturi 105 and creates a vacuum at throttle valve diaphragm 120. The butterfly valve is operated to allow vacuum at throttle valve diaphragm 120.
The fuel from fuel tank is a mixture of fuel and oil. The flow of fuel to float bowl 180 is controlled by floater 145 and float valve 150. The float valve 150 is placed on the floater 145. The level of fuel increases in float bowl 180 and induce the floater 145 to gradually close the inlet of float bowl 180 through float valve 150. Also, bendable float valve 150 is used to adjust the level of fuel in the float bowl 180. During the course of starting the engine, choke plunger 175 is pulled and a small volume of fuel is flown into the venturi 105. Jets are operated to supply continuous and controlled flow of fuel from float bowl into the venturi 105. Also, secondary intake is opened and outer air (air intake) is sucked by the pilot air jet 140 into the venturi 105. The pilot jet 160 is opened to allow small amount of fuel, which is flown into venturi 105. Outer air and fuel is mixed and flown at the pilot mixture screw 165. Flow of air and fuel mixture is adjusted by pilot mixture screw 165. The choke plunger 175 sprays out extra fuel. Then, choke plunger 175 is closed to attain idling state of engine. During the throttle, the throttle plate 170 is opened to create a vacuum space (passage) at throttle valve diaphragm 120. The vacuum passage retracts the throttle valve diaphragm 120. The jet needle 135 attached with throttle slide 125 is raised to open main jet 155 and needle jet 130. The fuel from float bowl 180 is passed through main jet 155 and needle jet 130. Air is flown from outer air inlet 110 of engine (primary). The air and fuel is mixed and passed towards the combustion chamber 115. The angle of throttle plate 170 determines the positions of throttle slide 125, amount of fuel to be sucked and air to be mixed at the venturi 105. Also, size of main jet 155 and needle jet 130 determines amount of fuel flow into the venturi 105. When the throttle is high, the throttle plate 170 is fully opened and vacuum occupies the passage of throttle valve diaphragm 120. And, throttle slide 125 and needle jet 130 are raised high. The large amount of air and fuel is passed through the venturi 105 and passed to the combustion chamber 115. During idling of engine, the throttle plate 170 is closed, throttle slide 125 retorts to original position which closes the needle jet 130 and restricts air from outer air inlet 110. The operation of the conventional carburetor is further described in the book titled “Holley: Carburetors, Manifolds and Fuel Injection”, authored by Bill Fisher which is incorporated herein by reference. Details of an example valve are described in India Patent Application number 2664/CHE/2013, which is incorporated herein by reference.